Nowadays, combustion is the prime energy source because of its universality of applications. But the increase in its usage causes pollution problems, which are affecting the planet.
Presently, the problem created by contaminant emissions from combustion sources constitutes a significant contribution to pollution and related environmental concerns. A number of measures, techniques or devices for reducing the contaminant emissions (i.e., both in particulate and gaseous form) in combustion exhaust streams have been proposed.
For example, a number of proposals to use filters to capture and remove particulates and environmentally noxious gases, such as ozone, sulfurous acids, and carbon monoxide, among others, have been made. A variety of filters have been proposed, including for example, electrostatic filters, sleeve type filters, plate filters, and others. The cost and efficacy of different filter systems varies and cheaper, more cost effective solutions are desired.
It has also been proposed to rinse exhaust streams with showers of water or other liquid(s) to wash from the exhaust streams particulates and noxious gases. Unfortunately, these methods contribute little or nothing to the reduction of contaminants liberated to the environment, do not provide desired pollution reduction, or are too costly.
In the case of conventional gas washing devices applied to mobile sources, specifically exhaust pipes of vehicles, the main disadvantage is the necessity for using great amounts of water. High volumes of fluid are necessary because the washing liquid is applied to high velocity, high temperature (e.g., typically at temperatures of well over 100° C. or more) streams that leads to significant evaporation into the exhaust stream, resulting in the emission of a moisture enriched exhaust stream. Chilean Patent Application Publication No. 615-99 describes a typical spraying device located onto the exhaust pipe, which produces a water curtain for conveying the particles to a container or tray adjacent to the pipe, producing the above-described problems.
Chilean Patent No. 40,474 discloses a wet filter for cleaning flue gases comprising an external cylindrical shroud and a coil at the upper end of the shroud. Fumes passing through the coil are washed by water, but the system does not effectively retain small particulates or noxious gases from the flue stream.
Thus, a need exists for a way to reduce the emission of pollutants from the exhaust streams of combustion sources, either particulates or gases, such as internal combustion engines, which are more effective and cheaper to implement and operate than current available means.